Weather radar system and method with path attenuation shadowing

ABSTRACT

An avionic weather radar system and method can sense a path attenuation condition using radar returns of received via a radar antenna onboard the aircraft. Images of weather can be displayed using an outside source and the radar returns. The images are displayed using information from the outside source when the path attenuation condition is sensed. The images can be displayed using speckled areas, cross hatched areas or other symbols to represent the information from the outside source. The images of the weather can be provided on an avionic display.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. Pat. No. 9,599,707, filedJan. 23, 2014, which is incorporated herein by reference in its entiretyand for all purposes.

BACKGROUND

The present disclosure relates generally to the field of weather displaysystems. More particularly, the present disclosure relates to a weatherdisplay system and method configured to display weather which isobscured by path attenuation.

Weather display systems are often used to alert operators of vehicles,such as aircraft pilots, of weather hazards in the area near thevehicle. Conventional weather display systems are configured to displayweather data in two dimensions and often operate according to ARINC 453and 708 standards. A horizontal plan view provides an overview ofweather patterns near an aircraft mapped onto a horizontal plane.Generally the horizontal plan view provides indications of precipitationrates in the vicinity of the aircraft (images of weather). Red, yellow,and green colors are used to symbolize areas of respective precipitationrates, and black color symbolizes areas of very little or noprecipitation. Each color is associated with radar reflectivity rangewhich corresponds to a respective precipitation rate range. Redindicates the highest rates of precipitation while green represents thelowest (non-zero) rates of precipitation. Certain displays can alsoutilize a magenta color to indicate regions of turbulence.

Onboard avionic weather radar systems (e.g., x-band weather radarsystems) cannot always penetrate or sense areas beyond intenseprecipitation or rainfall. Accordingly, cells (e.g. storms) behind anearby line of cells may be shadowed by the closer cells. This shadowingby the closer cells can deprive the pilot of a view of the completeweather situation through which the aircraft is flying. Conventionalavionic weather radar systems such as the WX2100 weather radarmanufactured by Rockwell Collins, Inc. can execute a path attenuationcompensation (PAC) algorithm that flags any radial where the radarreturn is too badly attenuated to be corrected. Path attenuation isdescribed in U.S. Pat. No. 5,047,775 incorporated herein by reference

Conventional displays can mark such radials with a yellow bar and/orprovide the text “PAC Alert” so that the pilot can be aware that hiddenweather may be behind displayed weather cells. However, such systems donot provide an indication of whether or not weather actually existsbehind the weather cell or what type of weather exists behind a weathercell.

Thus, there is a need for a weather information display that providesmore information than a conventional display. Further, there is a needfor a threat depiction system and method that can augment the display ofinformation when weather detection is obscured by path attenuation.Further still, there is a need for an avionic weather system including apath attenuation algorithm that provides an indication of weather beyondthe attenuating cell. Yet further, there is a need for a system andmethod that displays weather despite path attenuation issues. Yetfurther, there is a need for a weather display that can display weatherimages using merged data from two different sources.

SUMMARY

An exemplary embodiment relates to a method of displaying imagesassociated with weather near an aircraft. The method includes sensing apath attenuation condition using the radar returns and displaying theimages of the weather using an outside source and the radar returns. Theimages of the weather are displayed using information from the outsidesource when the path attenuation condition is sensed.

Another exemplary embodiment relates to an avionic weather radar system.The avionic weather radar system includes a processor configured tosense a path attenuation condition using radar returns received via aradar antenna onboard the aircraft. The processor is also configured tocause images of weather to be displayed using outside source and theradar returns. The weather is displayed using information from theoutside source when the path attenuation condition is sensed.

According to certain embodiments outside sources can be another weatherradar source or data from the onboard weather radar system operating ata different frequency. In other embodiments, the outside source can be anon-radar airborne source, a light detection and r ranging (LIDAR)source, an infrared source (e.g., infrared sensor/camera), etc.).

Another embodiment relates to a method of displaying images associatedwith weather near an aircraft. The method includes receiving radarreturns associated with a radar antenna of the aircraft, and receivingdata from a source remote from the aircraft. The method also includesdisplaying the images associated with the weather using at least a firstcolor, a second color and a third color associated with a respectivefirst precipitation rate or threat range, a respective secondprecipitation rate or threat range, and a respective third precipitationrate range or threat level. The first precipitation rate range or threatlevel is less than the second precipitation rate range or threat leveland the third precipitation rate range or threat level is more than thesecond precipitation rate range or threat level. The images associatedwith the weather include at least a first image provided using the radarreturns and a second image provided using the data from the sourceremote from the aircraft. The second image is provided at a rangegreater than a range of a path attenuation condition.

Another embodiment relates to a system comprising an electronicprocessor configured to provide the images of weather on a displayaccording to any of the methods described above. Another embodimentrelates to one or more non-transitory computer-readable storage mediahaving instructions stored thereon that are executable by one or moreprocessors to execute one or more of the methods described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingfigures, wherein like reference numerals refer to like elements, inwhich:

FIG. 1 is a general block diagram of an exemplary weather radar systemthat may be used, for example, on an aircraft according to an exemplaryembodiment;

FIG. 2 is a more detailed block diagram of the weather radar system ofFIG. 1 according to an exemplary embodiment;

FIG. 3 is a flow diagram of an exemplary process for generating imagesof weather using the system illustrated in FIG. 1 according to anexemplary embodiment;

FIG. 4 is a drawing of a screen including display images of weather on aconventional display;

FIG. 5 is a drawing of a screen including display images of the weatherillustrated in FIG. 4 provided by the system illustrated in FIG. 1including images derived from weather data from an outside source duringa path attenuation condition according to an exemplary embodiment;

FIG. 6 is a drawing of a screen including display images of the weatherillustrated in FIG. 4 provided by the system illustrated in FIG. 1including images derived from weather data from an outside source duringa path attenuation condition according to another exemplary embodiment;

FIG. 7 is a drawing of a screen including display images of the weatherillustrated in FIG. 4 provided by the system illustrated in FIG. 1including images derived from weather data from an outside source duringa path attenuation condition according to another exemplary embodiment;and

FIG. 8 is a drawing of a screen including display images of the weatherillustrated in FIG. 4 provided by the system illustrated in FIG. 1including images derived from weather data from an outside source duringa path attenuation condition according to another exemplary embodiment.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplaryembodiments in detail, it should be understood that the application isnot limited to the details or methodology set forth in the descriptionor illustrated in the figures. It should also be understood that theterminology is for the purpose of description only and should not beregarded as limiting. As discussed below, the systems and methods can beutilized in a number of display devices for various types ofapplications or sensing systems.

Referring generally to the figures, systems and methods for providingvisual representations of weather in proximity to an aircraft or othervehicle are provided. According to one embodiment, weather images aredisplayed even when sensing the weather is blocked by path attenuationcondition. For example, an embodiment of the system and method describedherein can advantageously display blocked cells using a source ofweather data or information remote from the aircraft. The blocked cellscan advantageously be depicted using display formats compatible withARINC 453, and ARINC 661 avionic display platforms. The display ofblocked cells advantageously gives pilots a more complete view ofweather conditions.

In one embodiment, the images are displayable on at least one ofnavigation (NAV) displays, primary flight displays, electronic flightbag displays, tablets such as iPad® computers manufactured by Apple,Inc. or tablet computers, synthetic vision system displays, head updisplays (HUDs), wearable displays, Google glasses, etc. In addition,the on-board sensed weather data and remote weather data can besynchronized before merging the data for display, according to oneembodiment.

Referring generally to FIGS. 1 through 3, systems and methods that maybe used to generate images of weather are shown and described accordingto exemplary embodiments. In some embodiments, only weather associatedwith radar returns received by a radar antenna onboard the aircraft aredisplayed when a path attenuation condition does not exist.Alternatively, weather data from a remote source can be merged with theweather associated with onboard weather radar return data and themerging algorithm can use a path attenuation factor to weight the datafor the merging operation. In another embodiment, the merging operationcan choose the remote data at ranges past the path attenuation conditionover the data from onboard radar returns, or can choose the remote dataat a range past the path attenuation condition on a radial basis overthe data from onboard radar returns. According to another embodiment,weather within a threshold range is depicted using data derived fromreturns received onboard the aircraft, and weather outside of thethreshold range is depicted using data from a remote source.Advantageously, systems and methods according to certain embodiments canutilize storm motion vectors from the information from the remote source(e.g., ground-based source) to adjust the position of the weather datafrom the remote source (e.g., NEXRAD data) to compensate for the delay.The data from the remote source can be differentiated visually from anonboard data as there may be residual error in what is presented in thedata from the remote source.

Referring specifically to FIG. 1, a block diagram of a weather radarsystem 200 that may be used, for example, on a vehicle such as anaircraft is depicted according to an exemplary embodiment. In oneembodiment, system 200 may be an avionics multi-scan, systemmanufactured by Rockwell Collins, such as the RTA-4218 MULTISCAN weatherradar system or WXR-2100 weather radar system configured in accordancewith the principles described herein. System 200 includes a weatherimage module 212 and a weather image module 214 in one embodiment.Modules 212 and 214 can be a circuit, module, software program orroutine. Weather image module 212 advantageously determines the presenceof weather at ranges and locations (and altitudes in certainembodiments) for display to the pilot of an aircraft.

Weather image module 212 may be used to create a spatially correctweather interpretation (e.g., weather images) that may be displayed inthe range, altitude, and/or time domains. A combination of horizontaland selected vertical antenna beams may facilitate the collection ofradar return data (IQ data) that can be used to compute parameters toconstruct an accurate weather model. The weather model may bealtitude-based, and an estimate of the reflectivity based on radarreturns may be obtained for any scan angle, range, and altitudecombination. Weather image module 212 may store the altitude-basedweather model in a memory 206, and the weather model may be used toextract weather information in a defined manner (e.g., based on useractions). Weather image module 212 can use data from remote source 152and data from onboard the aircraft associated with radar returnsreceived by radar antenna 104.

Avionics weather radar system 200 includes a weather radarreceiver/transmitter 102, weather radar adjustable antenna 104, aprocessor 208, and a memory 206 (e.g., a multi-scan, multi-tilt anglememory) in one embodiment. System 200 also includes a tilt control 203for automatically controlling the tilt angle (mechanical or electronic)of the antenna 104 in one embodiment; this auto control may include anadditional manual control feature as well.

Memory 206 may be capable of storing in a readily addressable andrapidly retrievable manner at least two data sets resulting from two ormore antenna sweeps at different angles. Memory 206 can include any typeof machine-readable storage device capable of storing radar returns orassociated data for analysis/processing by processor 208. In someembodiments, memory 206 can store parameters of a weather model. Thedata in memory 206 can represent factors for a mathematical relationshipdefining reflectivity as a function of altitude in one embodiment. Thedata in memory 206 can be used by path attenuation module 214 todetermine whether a path attenuation condition exists. Although amulti-scan, multi-tilt scanning and data sets are described, it shouldbe understood by one of ordinary skill in the art that a single scan ofdata may also be used in some embodiments.

Memory 206 can also be a three dimensional storage buffer for storingweather radar parameters according to X, Y and Z coordinates accordingto one embodiment. The storage of radar data and the form of the weatherdata stored therein is not disclosed in a limiting fashion. A variety ofstorage techniques for weather data can be used without departing fromthe scope of the invention.

Weather data from returns received by antenna 104 and weather data fromremote source 152 can be stored in memory 206. The weather data can bebased on received horizontal and/or vertical scans and from otheraircraft or ground based sources. The weather data from remote source152 can be received using a communications unit 153, such as a radio orother wireless communication device.

In some embodiments, the data may be stored as a mathematical equationrepresentation of the information. The mathematical equationrepresentation may be a piecewise linear function, piecewise nonlinearfunction, coefficients of a cubic spline, coefficients of a polynomialfunction, etc. that represent vertical representations of the weatherbased on the horizontal scan data and/or horizontal representation ofthe weather based on the vertical scan data. The function may be anequation based on weather parameters that may be sensor driven, modeldriven, a merger of sensor and model, etc. Although horizontal scan datais described, alternative embodiments may include X, Y Cartesiancoordinates, rho/theta input, latitude and longitude coordinates,altitude, etc. Weather may be estimated for any required point in spacewith the vertical dimension being the subject of the weather equation.

Display 110 can be part of an avionic multi-function display (MFD) unitin one embodiment. In some embodiments, display 110 may be any of avariety of display types, such as a navigation display, an electronicflight bag, a tablet computing device, a synthetic vision system, aheads up display (HUD), a dedicated weather display, or another type ofdisplay system. In some embodiments, display 110 may be a remote displaynot included within a cockpit of the aircraft, such as a ground-basedsupport display or remote display configured to display informationregarding whether near an unmanned aerial vehicle (UAV).

Processor 208 may be included as part of a multi-scan, multi-tilt angleweather radar system and may perform the customary functions performedby a conventional weather radar return processing unit. Processor 208may also perform several additional operations based upon the additionaldata and/or instructions provided in memory 206. In general, processor208 can merge or cross qualify portions, or ranges, of the radar returnsof several different antenna sweeps at several different tilt angles, sothat a single, relatively clutter-free image may be presented to thepilot based upon the several separate scans. The radar returns may beprocessed by processor 208 to generate a three-dimensional weatherprofile of the weather near the aircraft.

System 200 may perform a scanning operation by transmitting at least twobeams at different tilt angles. In some embodiments, system 200 may usea global positioning system (GPS), terrain database, or other tool tocontrol the tilt control 203. Data obtained from the radar returns(e.g., reflectivity data) may be stored in memory 206. For example,known ground clutter may be removed from each of the returns usingground clutter suppression techniques.

Referring again to FIG. 1, in some embodiments, processor 208 may beconfigured to store parametric characteristics of the vertical extent ofthe weather in memory 206 instead of detecting and storing the entirereflectivity profile in a traditional three-dimensional memory. Forexample, since the radar knows current altitude and outside airtemperature, processor 208 can be configured to estimate the altitude ofthe local atmospheric freezing layer. Further, processor 208 canestimate the height of the troposphere based on latitude, season, ormore precise FMS data. Using this information and radar elevation scandata collected from scanning processes (e.g., normal MULTISCAN two-tiltor three-tilt processes), processor 208 may generate a linear fit of thereflectivity data from the ground to the freezing layer and anotherlinear fit between the freezing layer and top of the troposphere.

Some embodiments may use more complex curve fits. Specific curve fitscan be utilized depending on geographical location, time of day, time ofyear, etc. For example, over Europe, a linear curve fit may suffice todetermine vertical reflectivity between freezing layer and troposphereheight whereas a second order fit may be required over the equatorialPacific. A tag can be given to each cell denoting the specific order ofthe data fit and, correspondingly, the method used to obtain verticaldata from the stored parameters. As additional data is collected,perhaps through dedicated vertical scans of convective cells, thefunctions can be updated or increased in complexity in order to improvetheir accuracy.

Processor 208 may process weather radar returns to identify or sense thepresence of weather in front of or in view of the aircraft. Weatherimage module 212 may utilize the altitude and the range to the weatherto generate a vertical profile associated with the weather. Weathermerge module 212 may scan across an array of azimuths to generate athree-dimensional weather profile of the weather near the aircraft,which may be stored for later presentation or immediately presented ondisplay 110. Weather images can be displayed on either view screen 111or 113 or both screen 111 and 113. Screens 111 and 113 plan view onlydisplays in one embodiment. Although vertical profiles are discussedherein, system 200 includes embodiments that do not use vertical profileprocessing and/or that do not display vertical profiles.

In some embodiments, additional visual indicators other than therepresentation of weather are provided on screens 111 or 113. In someembodiments, a range and bearing matrix having range markers indicatingdistance from a current position of the aircraft and bearing markersindicating azimuths from a current flight path or bearing of theaircraft may be provided and may assist the pilot in cognitiverecognition of weather features from the pilot's perspective.

With reference to FIG. 2, processor 208 can provide a mean velocityparameter 260 and a spectral width parameter 262 derived from weatherradar returns. Alternatively, other types of velocity parameters can beutilized. In addition, processor 208 can provide a reflectivityparameter 264 and a range parameter 268 to circuit 212. Computed rangeor range parameter 268 along with scan angle position can be used toplot the position of weather on display 110. Processor 208 can alsoreceive a temperature parameter 66, an azimuth 68, a position 70, a date72, flight plan 75 and time 74. Alternatively, a separate temperaturesensor 66 can be coupled to processor 208. Parameters 260, 262, 264, and268 can be computed by processor 208 using data stored in memory 206.

Path attenuation module 214 receives weather radar returns associatedwith antenna 104 and determines whether a path attenuation conditionexists. Module 214 can employ an algorithm similar to the algorithmsemployed in the RTA-4218 MULTISCAN™ radar system to determine whetherX-band weather radar returns are experiencing a path attenuationcondition. These algorithms generally determine whether returns beyond arange associated with large reflections have been too badly attenuatedfor compensation. If so, the path attenuation condition warning isprovided.

In one embodiment, the path attenuation condition can be sensed whenexpected returns (e.g., noise returns) fall off rapidly. The pathattenuation condition can be sensed on a radial basis. Alternatively,weather data from remote source 152 can be compared to weather data fromradar returns received by radar antenna 104 to determine if a pathattenuation conditions exists. For example, if there is a cell or stormat a particular range in a particular azimuth range according to remotedata and the weather radar returns do not show any storms or cell beyondthat particular range in the particular azimuth range, then pathattenuation module 214 can determine that a path attenuation conditionexists. Module 214 may consider whether a storm is in front of themissing storm from the remote data. Temporal correlation can benecessary in certain embodiments as returns received by antenna 104generally provide more current data than weather data received viacommunications unit. In one embodiment, data from source 152 includesstorm vector information, and the locations of the cells are adjustedwith respect to time using the storm vector information.

If a path attenuation condition exists, weather image module 212 canutilize weather data from remote source 152 and radar returns to providea screen 111 using weather data from a remote source. If a pathcondition does not exist, weather image module 214 can provide a screen113 that provides images only using weather data derived from radarreturns received on antenna 104. Screen 111 can include both imagesderived from weather data from remote source 152 and weather dataderived from returns received an antenna 104. The images derived fromweather data from remote source 152 and weather data derived fromreturns can be spatially correlated using time of sensing informationand storm vector values. The storm vector values can be from a Nowcastor forecast weather data source such as the Corridor Integrated WeatherSystem (CIWS) or Consolidated Storm Prediction for Aviation (COSPA)weather data source in one embodiment. Along with storm vectorinformation, growth and decay information can be received, which may beused to increase or decrease the size, shape, and intensity of theweather data displayed in accordance with time in one embodiment.

Weather data stored in memory 206 can include weather data from remotesource 152 (FIG. 1) and weather data associated with radar returnsreceived an antenna 104. The weather data can include a time of sensingdata and storm vector data for temporal and spatial correlation.

In one embodiment, if a path attenuation condition exists, weather imagemodule 212 can utilize weather data from another aircraft or otheronboard weather sources and radar returns associated with antenna 104 toprovide a screen 111. The weather data can be from another weather radarsource or data from the onboard weather radar system operating at adifferent frequency. The different frequency can be a millimeterfrequency, a Ka band, frequency, a W band frequency etc. In otherembodiments, the weather data can be from a non-radar airborne source (aLIDAR source, an infrared source, etc.).

With reference to FIGS. 1-3, processor 208 and weather image module 212and path attenuation module 214 can utilize process 140 to provideimages on display 110 in one embodiment. At a step 142, processor 208receives weather data associated with weather returns at multiple tiltangles from antenna 104 in one embodiment. Alternatively, the radarreturns do not have to be at multiple tilt angles in certainembodiments. At a step 144, weather image module 212 determines thepresence of, location of, and range of weather from weather data derivedfrom radar returns in one embodiment.

At a step 145, path attenuation module 214 determines if a pathattenuation condition exists in one embodiment. At a step 146, if a pathattenuation condition exists, weather data from remote source 152 areadjusted for spatial and temporal correlation in accordance with oneembodiment. At a step 148, the weather data from remote source 152 andweather data derived from radar returns from antenna 104 are merged inone embodiment. At a step 150, weather images are generated using themerged data in one embodiment.

If a path condition does not exist at step 145, weather images can begenerated at step 150 using only return data from radar returns receivedby radar antenna 104 in one embodiment. In one embodiment, a pathattenuation factor can be utilized to select weather data for merging.The weather data from source 152 can be merged with the radar returndata to create weather images in one embodiment. For example, if theattenuation factor indicates substantial attenuation at a particularazimuth and range, weather images can be provided using a greaterpercentage of data form source 152 at that range in one embodiment. Ifthe attenuation factor indicates a complete path attenuation condition,then the data from source 152 is entirely used to provide the image atthat range and azimuth in one embodiment. Further, data can be merged inaccordance with its temporal standing. More recent data is givenpreference over older data in one embodiment. In one embodiment, imagesare provided using data from source 152 at ranges beyond a thresholdrange, and images are provided using data from radar returns received byantenna 104 at ranges below the threshold range.

Processor 208 and weather image module 212 cause display 110 to displayareas associated with weather data from remote source 152 differentlythan weather images derived from radar returns from antenna 104 in oneembodiment. Weather images using data from remote source 152 can bedisplayed using outlines, cross-hatching, uniformly organized speckles,etc. The outlines, cross-hatching and speckles can have red, yellow, orgreen color according to standard precipitation rates in one embodiment.In one embodiment, the cross-hatched regions are provided with abackground color corresponding to the precipitation rate and a linecolor for the cross hatching differs from the background color.

The speckled pattern or cross hatched regions can either be bounded(e.g., outlined) or unbounded and can have a variety of shape profilesincluding rounded or straight edges in one embodiment. The speckles canvary in shape and size to represent age of data in one embodiment. Thecross hatching can also vary in thickness to represent age of data inone embodiment. According to another embodiment, boundary color can bethe same or different as the speckled colors. According to anotherembodiment processor 208 and weather image module 212 cause display 110to display areas associated with weather data from remote source 152 asoutlined regions without cross hatching and speckles in one embodiment.

In some embodiments, process 140 may be implemented using instructionsstored on a machine-readable medium (e.g., memory 206) and executed on aprocessor (e.g., processor 208). Processor 208 may be configured tooperate system 200 as a pulse Doppler multi-scan, multi-tilt angle radarsystem or a volumetric radar system in which radar beams are produced atmore than one tilt angle. Processor 208 receives radar returns throughreceiver/transmitter circuit 102.

Processor 208 can receive the radar returns (or signals/data relatedthereto) directly or through memory 206 at a step 142.Receiver/transmitter circuit 102 can be a single path or can haveseparate circuits for a receive path and a transmit path. Processor 208may determine power associated with the radar returns.

With reference to FIG. 4, a conventional screen (or portion thereof)displays weather images 402 on a screen 400. Images 402 have a firstcolor 404, a second color 406 and a third color 408. Colors 404, 406 and408 symbolize a respective precipitation rainfall rate range and can bered, yellow and green respectively. Weather images 405 and 407 aredisplayed in a fashion similar to weather images 402.

A PAC alert is provided on screen 400 as a bar 412 as well as a textualmessage 414 stating the term “PAC ALERT”. Bar 412 indicates the radialsthrough which the path attenuation condition exists and is provided on arange arc 416 with azimuth indications. Accordingly, the pilot is awarethat additional storms may exist beyond the range of weather images 402.Since bar 412 is not provided behind weather images 405 which aredisplayed in a similar fashion to weather images 402, the pilot knowsthat weather does not exist beyond the range of weather images 405.

With reference to FIG. 5, a screen 500 or portion of a screen isprovided by system 200 in one embodiment. Weather images 502 areprovided behind weather images 402 (further in range from the aircraft).Weather 502 is generated by weather image module 212 in response toweather data from remote source 152. Weather 502 is cross-hatched andincludes colors 404, 406 and 408 as background in one embodiment. Theline color for the cross hatching can be white, black or another color.Weather images 405 and weather images 407 on screen 500 are notdifferent from their depiction in screen 400 because the pathattenuation condition is not associated with the radials correspondingto images 405 and 407. Advantageously, system 200 allows weather images502 to be viewed by the pilot despite a path attenuation condition dueto the weather associated with images 402. In one embodiment, colors404, 406 and 408 in FIGS. 6-8 can represent a threat level or range.

With reference to FIG. 6, a screen 600 or portion of a screen isprovided by system 200 in one embodiment. Screen 600 includes weatherimages 402, 405, and 602. Weather images 602 correspond to weatherimages 502 on screen 500 and are shown in an outline form indicatingthat weather images 602 are provided from data from remote source 152according to one embodiment. The outline can be color coded to indicateprecipitation rates using red, yellow and green according to oneembodiment. Weather images 402, 405 and 407 are displayed as on screens400 and 500 in FIGS. 4 and 5.

With reference to FIG. 7, a screen 700 or portion of a screen isprovided by system 200 in one embodiment. Screen 700 includes weatherimages 402, 405, and 702. Weather images 702 correspond to images 502and are shown as speckled regions indicating that weather images 502 arederived from data from remote source 152 according to one embodiment.The speckles can be color coded to indicate precipitation rates usingred, yellow and green according to one embodiment. Weather images 402,405 and 407 are displayed as on screens 400 and 500 as in FIGS. 4 and 5.

Screen 700 can also include a PAC Alert message 704 and/or a bar 706indicating the radials affected by the path attenuation conditionaccording to one embodiment. Bar 706 can be yellow or anotherappropriate color. Bar 706 can be provided on the outer most range arcin one embodiment. Message 704 and bar 706 can also be used on screens500 and 600 according to one embodiment.

With reference to FIG. 8, a screen 800 is provided by system 200 in oneembodiment. Screen 800 includes weather images 402, 405, and 802. Screen800 includes a range marker 828. Marker 828 can be a 100 nautical mile(nm) range arc or marker from the aircraft as represented by symbol 826.Alternatively, marker 828 can indicate other ranges including rangesselectable by the pilot. A numerical indicator can be provided at a leftend of marker 828 to indicate the current range. Screen 800 alsoincludes weather images 822 at range greater than the range representedby marker 828 in one embodiment. Marker 828 can provide delineationbetween weather images 822 and weather images 402, 405, and 802. U.S.Pat. No. 6,441,773 assigned to the assignee of the present applicationand incorporated herein by reference shows exemplary displays using adelineation marker between types of weather data.

Weather images 802 correspond to images 502 and are configured toindicate that weather images 802 are derived from data from remotesource 152 according to one embodiment. Weather images 402, 405 and 407are displayed as on screens 400 and 500 as in FIGS. 4 and 5.

Weather images 822 are derived from data from source 152. In oneembodiment, system 200 uses data from source 152 at greater rangesbecause weather is best sensed via radar antenna 104 at shorter ranges(e.g., 60 nm, 80 nm, and 100 nm) in one embodiment. In anotherembodiment, system 200 uses data from source 152 for areas outside theazimuth capabilities of antenna 104. Data from returns received byantenna 104 are updated much more rapidly than outside sources likeNEXRAD sources. Weather images 822 can be derived from data from outsidesource 152 at greater ranges because the relevant weather can be sampledmore accurately via antenna 104 as the aircraft comes closer to it asthe aircraft travels along flight path 824. The locations of weatherimages 822 can be adjusted in accordance with time and vector parametersin one embodiment. Screen 800 can also include a PAC Alert message 704and/or a bar 706 indicating the radials affected by the path attenuationcondition on marker 820 according to one embodiment. Weather imagemodule 212 can merge the weather data from source 152 with the radarreturn data associated with antenna 104 by using a threshold range orgreater to choose the weather data from source 152 and choosing theweather data from source 152 when a path attenuation condition exists tocreate screen 800 in one embodiment. In one embodiment, a zone aroundmarker 828 can define an area where merged data is used to provideweather images. In one embodiment, the merged data includes radar returndata and data from source 152, each weighted according to its range fromthe aircraft where radar return data is more heavily weighted the closerit is to the aircraft. The weather images in the merged data area can beconfigured similar to images 502, 602, 702, or 802. In one embodiment,weather images 822 can be depicted at a lower brightness, luminance orintensity level or similar to images 502, 602, 702, or 802 to indicatethey are derived from data from outside source 152. In one embodiment,the brightness, luminance or intensity level is varied to represent theage of data associated with images 822.

The disclosure is described above with reference to drawings. Thesedrawings illustrate certain details of specific embodiments thatimplement the systems and methods and programs of the presentdisclosure. However, describing the disclosure with drawings should notbe construed as imposing on the disclosure any limitations that may bepresent in the drawings. The present disclosure contemplates methods,systems and program products on any machine-readable media foraccomplishing its operations. The embodiments of the present disclosuremay be implemented using an existing computer processor, or by a specialpurpose computer processor incorporated for this or another purpose orby a hardwired system. No claim element herein is to be construed underthe provisions of 35 U.S.C. § 112, sixth paragraph, unless the elementis expressly recited using the phrase “means for.” Furthermore, noelement, component or method step in the present disclosure is intendedto be dedicated to the public, regardless of whether the element,component or method step is explicitly recited in the claims.

As noted above, embodiments within the scope of the present disclosureinclude program products comprising machine-readable storage media forcarrying or having machine-executable instructions or data structuresstored thereon. Such machine-readable storage media can be any availablemedia which can be accessed by a general purpose or special purposecomputer or other machine with a processor. By way of example, suchmachine-readable storage media can comprise RAM, ROM, EPROM, EEPROM, CDROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium (e.g., non-transitorymedium) which can be used to carry or store desired program code in theform of machine-executable instructions or data structures and which canbe accessed by a general purpose or special purpose computer or othermachine with a processor. Combinations of the above are also includedwithin the scope of machine-readable storage media. Machine-executableinstructions comprise, for example, instructions and data which cause ageneral purpose computer, special purpose computer, or special purposeprocessing machine to perform a certain function or group of functions.

Embodiments of the disclosure are described in the general context ofmethod steps which may be implemented in one embodiment by a programproduct including machine-executable instructions, such as program code,for example, in the form of program modules executed by machines innetworked environments. Generally, program modules include routines,programs, objects, components, data structures, etc., that performparticular tasks or implement particular abstract data types.Machine-executable instructions, associated data structures, and programmodules represent examples of program code for executing steps of themethods disclosed herein. The particular sequence of such executableinstructions or associated data structures represent examples ofcorresponding acts for implementing the functions described in suchsteps.

Embodiments of the present disclosure may be practiced in a networkedenvironment using logical connections to one or more remote computershaving processors. Logical connections may include a local area network(LAN) and a wide area network (WAN) that are presented here by way ofexample and not limitation. Such networking environments are commonplacein office-wide or enterprise-wide computer networks, intranets and theInternet and may use a wide variety of different communicationprotocols. Those skilled in the art will appreciate that such networkcomputing environments will typically encompass many types of computersystem configurations, including personal computers, hand-held devices,multi-processor systems, microprocessor-based or programmable consumerelectronics, network PCs, servers, minicomputers, mainframe computers,and the like. Embodiments of the disclosure may also be practiced indistributed computing environments where tasks are performed by localand remote processing devices that are linked (either by hardwiredlinks, wireless links, or by a combination of hardwired or wirelesslinks) through a communications network. In a distributed computingenvironment, program modules may be located in both local and remotememory storage devices.

An exemplary system for implementing the overall system or portions ofthe disclosure might include a general purpose computing device in theform of a computer, including a processing unit, a system memory, and asystem bus that couples various system components including the systemmemory to the processing unit. The system memory may include read onlymemory (ROM) and random access memory (RAM) or other non-transitorystorage medium. The computer may also include a magnetic hard disk drivefor reading from and writing to a magnetic hard disk, a magnetic diskdrive for reading from or writing to a removable magnetic disk, and anoptical disk drive for reading from or writing to a removable opticaldisk such as a CD ROM or other optical media. The drives and theirassociated machine-readable media provide nonvolatile storage ofmachine-executable instructions, data structures, program modules, andother data for the computer.

It should be noted that although the flowcharts provided herein show aspecific order of method steps, it is understood that the order of thesesteps may differ from what is depicted. Also two or more steps may beperformed concurrently or with partial concurrence. Such variation willdepend on the software and hardware systems chosen and on designerchoice. It is understood that all such variations are within the scopeof the disclosure. Likewise, software and web implementations of thepresent disclosure could be accomplished with standard programmingtechniques with rule based logic and other logic to accomplish thevarious database searching steps, correlation steps, comparison stepsand decision steps. It should also be noted that the word “component” asused herein and in the claims is intended to encompass implementationsusing one or more lines of software code, and/or hardwareimplementations, and/or equipment for receiving manual inputs.

The foregoing description of embodiments of the disclosure have beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit the disclosure to the precise formdisclosed, and modifications and variations are possible in light of theabove teachings or may be acquired from practice of the disclosure. Theembodiments were chosen and described in order to explain the principalsof the disclosure and its practical application to enable one skilled inthe art to utilize the disclosure in various embodiments and withvarious modifications as are suited to the particular use contemplated.

What is claimed is:
 1. A method of displaying images of weather near anaircraft, the aircraft receiving radar returns through a weather radarantenna of the aircraft, the method comprising: sensing a pathattenuation condition using the radar returns; wherein the pathattenuation condition is sensed by determining when expected returnsfall off rapidly; and displaying the images of the weather using anoutside source and the radar returns in response to sensing the pathattenuation condition; wherein the images of the weather associated withthe outside source are displayed as a pattern, the pattern based on acharacteristic of the weather; wherein components of the pattern have adisplay characteristic based on a time of sensing the weather by theoutside source.
 2. The method of claim 1, wherein the images of theweather associated with the outside source are displayed to have anoutline.
 3. The method of claim 1, further comprising: displaying a lineat a range associated with the path attenuation condition, the lineconfigured to alert a viewer of a display.
 4. The method of claim 1,wherein the components of the pattern are uniformly distributed.
 5. Themethod of claim 1, wherein the display characteristic comprises at leastone of a size, shape, intensity, thickness, intensity, brightness, andluminance.
 6. The method of claim 1, wherein the images of the weatherdisplayed using the outside source are positioned on a display based ona motion vector and growth and decay information and the time of sensingthe weather.
 7. The method of claim 6, wherein the motion vector andgrowth and decay information and the time of sensing the weather is usedto compensate for a delay time associated with receiving informationregarding the weather from the outside source.
 8. An avionic weatherradar system, comprising: a processor composing a path attenuationmodule and a weather image module, wherein the path attenuation moduleis configured to determine a path attenuation condition usingcharacteristics of radar returns received via a radar antenna onboard anaircraft in response to a presence of the path attenuation condition andwherein the path attenuation module is configured to cause images ofweather to be displayed using a second source and the radar returns,wherein the weather is displayed within a boundary of the pathattenuation condition using information from the second source based onthe path attenuation condition being sensed, wherein the images of theweather associated with the second source have a display characteristicindicating that the images of the weather associated with the secondsource are based on the information from the second source, and whereinthe display characteristic varies based on a time of sensing theweather.
 9. The system of claim 8, further comprising: a display fordisplaying the images of the weather.
 10. The system of claim 8, whereinthe weather is displayed using at least a first color, a second color,and a third color associated with a respective first precipitation raterange or threat level, a respective second precipitation rate range orthreat level, and a respective third precipitation rate range or threatlevel, wherein the first precipitation rate range or threat level isless than the second precipitation rate range or threat range and thethird precipitation rate range or threat level is more than the secondprecipitation rate range or threat level.
 11. The system of claim 8,wherein the processor further provides a textual message indicatingdetection of the path attenuation condition.
 12. The system of claim 10,wherein the processor further provides an arc across an azimuth range ofthe path attenuation condition.
 13. The system of claim 12, wherein thearc across the azimuth range of the path attenuation condition includesazimuth indications.
 14. The system of claim 8, wherein weather imagesbeyond a particular range are displayed using data from the secondsource, the second source being an off aircraft source.
 15. The systemof claim 8, wherein the second source comprises another aircraft, aground-based radar system, a LIDAR source, an infrared source, or a datasource storing weather data from second radar returns having a differentfrequency than the radar returns received via the radar antenna onboardthe aircraft.
 16. The system of claim 8, wherein the processor isfurther configured to sense the path attenuation condition bydetermining an area where expected radar returns rapidly fall off. 17.The system of claim 8, wherein the processor is further configured tosense the path attenuation condition by detecting a storm or cell at aparticular azimuth range and determining that radar returns do notindicate a presence of a storm or cell beyond the particular azimuthrange.
 18. A method of displaying images associated with weather near anaircraft, the method comprising: receiving radar returns associated witha radar antenna of the aircraft; sensing a path attenuation condition,wherein the path attenuation condition is sensed by determining whenexpected returns fall off rapidly; receiving data from a source remotefrom the aircraft; and displaying the images associated with theweather, wherein the images associated with the weather comprise a firstimage provided using the radar returns and a second image provided usingthe data from the source remote from the aircraft, wherein the secondimage is provided at a range greater than a range of the pathattenuation condition, wherein the second image has a displaycharacteristic indicating that the second image is based on the datafrom the source remote from the aircraft.
 19. The method of claim 18,wherein the display characteristic comprises a boundary of the pathattenuation condition.
 20. The method of claim 18, wherein the data fromthe source remote from the aircraft is weather data provided from aremote aircraft or from a NEXRAD source.